In order to reduce risk of infection to health care professionals from potentially harmful bacteria present in various forms of liquid waste removed from a patient, such as blood, it is generally well-known to disinfect, as well as solidify, the liquid waste products. A suitable additive for both disinfecting and gelling liquid medical wastes is described in U.S.. Pat. No. 5,635,196, and marketed under the name PremiCide.TM., and carries Environmental Protection Agency Reg. No. 59839-1. PremiCide.TM. is available as a granulated powder. When a sufficient quantity is added to liquid medical waste, the liquid waste is rendered less hazardous due to the disinfectants in the powder, and safer to dispose of in its now-gelatinized state.
It is desirable to introduce desiccants, such as PremiCide.TM., into a suction canister (which, for clarity shall be referred to herein as a "medical waste container" or simply a "waste container") without disturbing the sealed condition under which such liquid waste is typically collected and stored. Exposing the contents of the liquid waste to the atmosphere surrounding the waste container risks airborne contamination of health care professionals in the vicinity, and spillage of the liquid waste inside the waste container.
Various attempts have heretofore been offered to introduce desiccants into a closed medical waste container. For example, Smith, U.S. Pat. No. 5,584,825, discloses a system for adding granulated powder immobilizing agents to a vacuum sealed medical waste container using an adapter having a circular area with score lines to facilitate the rupture of the circular area upon application of pressure to the base of a vessel holding the powdered material. Once the circular area is ruptured, the powder flows into the medical waste container. However, this system suffers from the drawback that there is no way to re-seal the circular area, and thus the vessel containing the powder must remain connected to the medical waste container to maintain the vacuum seal. Also, the delivery system shown in Smith only operates when there is negative pressure or suction to draw the powdered waste treatment material through the delivery system and into the waste container. As such, any interruptions in the suction causes the waste treatment material to stop flowing into the medical waste container. In addition, if such a closure delivery system were utilized while lead tubes were still connected to the waste container, the suction can undesirably draw powdered desiccants into the lead tubes, thus clogging the lead tubes and rendering the lead tubes ineffective for future use.
Middaugh et al, U.S. Pat. No. 5,185,007, describes various systems for introducing powdered desiccants to liquid medical waste containers. Several of the systems described therein store the waste treatment material in a reservoir in the form of a pouch which is broken in order to start the introduction of powder into the waste container. One of the embodiments describes a floating plug that is pushed into the liquid waste in order to commence the flow of the powder. However, none of the systems are capable of maintaining the vacuum seal after a supply of the powdered waste treatment material is removed from the system. Also, once the supply of powder is used, no more powder can be added to the system without compromising the integrity of the vacuum seal and exposing liquid waste inside the container to the surrounding environment.
Another system for the addition of powdered waste treatment to liquid waste containers is described in Bryant et al., U.S. Pat. No. 5,234,419, which shows a reservoir in the form of a canister that moves freely within the sealed container. The canister stores powdered waste treatment material. The canister is opened by manipulating the flexible liner of the waste container and removing the end caps of the canister. Such a system cannot be used with solid waste containers, and presents a significant risk of catastrophically puncturing the waste container when removing the end caps of the canister.
A further shortcoming of various earlier devices for introducing powdered waste treatment into waste collection containers has been the inability of such devices to prevent powder from undesirably collecting within the device. Collection of powder is undesired, as it may have a tendency to inhibit the flow of powder into the waste container or may prematurely stop the flow of powder altogether. Also, it wastes powdered material that remains trapped in the device, instead of flowing into the medical waste container. Powder inside the device can collect on any flat, horizontal surfaces in the interior of the device. Yet another drawback of earlier waste treatment delivery systems has been the inability to control the rate of flow of powdered waste treatment material into a waste container. When introducing a solidifying powdered waste treatment into 3000 cc fluid liner medical waste canisters, the powder must be dispensed slowly in order to avoid gel block.
Therefore, it is an object of the present invention to provide a reliable closure device that maintains the integrity of a sealed medical waste container before, during, and after addition of powdered desiccants to the liquid waste within the container. It is another object of the present invention to provide a safe way of opening and closing the closure device to selectively allow or stop the flow, as well as control the rate of flow, of powdered waste treatment material into a medical waste container. It is yet another object of the invention to provide a closure device that can be attached and removed from a bottle or similar vessel containing a supply of waste treatment material. It is a further object of the invention to provide a way of securely connecting the closure device to a variety of sizes of pour spout ports on medical waste container lids. An additional object of the present invention is to minimize the existence of flat, horizontal ridges inside the device so as to eliminate the undesired collection of powdered waste treatment material inside the device. The manner in which these and other objects of the present invention are accomplished will become clear from the following Summary of the Invention, the Detailed Description of the Invention, and the drawings.